Online marketplaces such as eBay have made it even easier for international sales of exotic animal parts such as ivory, rare animal skulls, horns, and other items banned for sale under state, federal and international law because they threaten endangered species.

To address the problem, the Peninsula Humane Society partnered with eBay to train volunteers to identify, report, and help investigate these illegal sales. In the first year, more than 2,000 items were removed from eBay after being identified by volunteers. In the first 3 months of 2013, some 1,300 products have been flagged.

I can see this program making a difference by watching the way the wording of ebay auction descriptions changes as sellers try to get further under the radar. For example, elephant ivory is illegal to sell on ebay, so sellers advertise real elephant ivory as "faux ivory" (but if you look at the pictures, plenty of the faux ivory is real).